Electric incandescent lamp



Juhe 14, 1932. i VAN ETAL 1,863,423

ELECTRIC INGANDESGENT LAMP Filed n.4, 1930 Patented June 14, 1932 UNITED STATES PATENT OFFICE JACOB VAN EGK AND FEKKO FREE, OF BOTTEBDAH, NEDKERLANDS; SAID FEKKES ASSIGNOR TO HENDRIX FEKKES EECTBIG INCANDESGELiT LAMP Application filed January 4, 1980, Serial 1T0. 418,816, and in Belgium August 9, 1929.

' electric lamps as efiicient as possible, by means of reflectors.

A very simple and cheap way of obtaining same will be described hereafter with reference to the figures of the accompanying drawig. l is a sectional view of a lamp;

Fig. 2 is another sectional view, but only of a ortion of a lamp;

ig. 3 is asectional view of the upper portion of a lamp according to a diflerent embodiment;

Fig. 4 is a section on line IVIV of Fig. 1;

Fig. 5 is a section on larger scale of the neck of the lamp shown in Fi 1.

With reference to these figures, a glass bulb a is formed with a neck I) and c is a separate glass element.

According to Fig. 1, the cross section of the bulb a is firstly parabolic from 9' to k and then straight from k to l, and the cross section of the glass element a is parabolic from m to n. The glass element 0 may or may not be provided at its upper end with a flan e, to which the neck I) is sealed,whereas the ower end of said element a has a tubular shape. The electrodes on leading-in wires pass through thistubular portion and are sealed therein. Under said glass element 0 is sealed a small destal f, in which the supporting wires or the filament are. fastened. These supporting wires may be straight, curved or bent at right angles.

The filament is located in a plane variably spaced from the vertex of the annular parabolic portion. Y

The electrodes or leading-in wires are curved or bent inside the bulb, in order to increase their length and thereby not to heat the glass to an undesirable degree.

An openin and short pipe are shown at g, which serve t e urpose of extracting the an and filling the ulb with the desired ases, after which 0 eration said pipe g is sea ed at a very short istan'ce from the neck I). For this purpose, an inner pipe may also be employed, said pipe forming an openinglthrough which the passage of the wires t rough 0 takes place, or therebelow, which pipe is sealed after use at its top end.

Fig. 3 shows a section of the upper portion of a lamp, in which parts of the bulb are straight,-but it must be understood that this upper portion of the bulb may also comprise straight and curved portions. Reflecting means are provided on the element 0," starting from a little above the level m and ending at the level n, and on a portion of the neck I) and on the bulb a from j to k or Z or further. These reflecting means may also be provided on the element a and the bulb a to terminate in a plane inclined to the lamp axis, such as wy.

The reflecting means are provided inside the glass or on the outer face of the neck, bulb and element 0, i. e. outside the inner part of the lamp. The reflecting means is coated with a substance, which does not conduct electricity, when it is provided on the outer faces of the elements. Care -must, of course, be taken that the two electrodes do not come in contact with each other or with the reflecting means.

We claim:

1. An incandescent electric lamp, comprising a glass bulb, a glass neck forming an extension of said bulb, an inner glass element sealed to the bulb at the top end there of and terminating in a tubular part, leadingin wires passing thrp'ugh said tubular part and sealed therein, a small pedestal sealed to said tubular part, supporting wires for r the filaments fastened to said pedestal and an opening and short pipe at the top end of' the neck for gas extracting and filling purposes, the pipe being cut short near the neck.

2. An incandescent electric lamp having a reflectin portion arranged around the filament, t e surface of this portion being substantially that generated by the revolution of a parabola about a line arallel to its axis, the bulb of the lamp having a neck of considerable section and a glass element of corresponding section and similar conformation sealedin said bulb, the lass element extending inside the bulb in t e shape of a tapered tubular projection, said projection forming with the adjacent bulb portion the above-mentioned parabolic reflecting portion, a glass pedestal secured to said Hojection, radial supporting wires for the ament supported y said pedestal, and electric leads assing through said element. 3. An incandescent electric lamp havin a reflecting portion arranged around the ament, the surface of this portion bein substantially that generated by the revo ution of a number of straight segments forming an angle with each other and approximating to a parabola about a line parallel to the axis of the parabola, the bulb of the lamp having aneck of considerable section and a glass element of corresponding section and similar conformation sealed in said bulb, the glass element extending inside the bulb in the shape of a tapered tubular projection, said projection forming with the adjacent bulb portion the above-mentioned reflecting portion, a glass pedestal secured to said proection, ra 'al supporting wires for the filament supported by said pedestal, and electri leads passing through said element.

In testimony whereof we signed hereunto our names.

J. VAN ECK. F. FEKKES. 

